The impact of T and N stage on long-term survival of rectal cancer patients in the community.

BACKGROUND AND OBJECTIVES

Use of the TNM staging system has been encouraged for rectal cancer patients. This study examined the impact of T and N stages on long-term survival as well as the performance of associated risk classification systems.

METHODS

Patients who underwent surgery for rectal adenocarcinoma from 1988 to 2004 were identified in the Surveillance, Epidemiology, and End Results (SEER) database. Kaplan-Meier survival analysis was performed for subgroups of patients defined by T and N stage.

RESULTS

For the overall population of 30,826 patients, both T and N stage significantly impacted overall survival (P < 0.001). N stage variably affected survival for subgroups of patients based on T stage, whereas T stage significantly affected survival regardless of N stage. A previously developed risk classification system that assigns one of four risk levels outperformed AJCC group staging in this cohort. Based on long-term outcomes, a modified risk classification system was constructed which was highly prognostic for long-term overall survival (P < 0.001).

CONCLUSIONS

Rectal cancer patients experience widely varying survival rates based on extent of disease. A new risk classification system is proposed that provides better prognostic information than AJCC group staging, suggesting current rectal cancer staging systems may be improved with appropriate revisions.